Fair Value Measurements - Schedule of Financial Instruments Not Measured at Fair Value on our Consolidated Balance Sheets (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Carrying value
Fair value of financial assets and liabilities
Loans receivable	$ 1,054.7	$ 828.5
Mortgages payable	43.0	81.3
Notes and bonds payable	23,157.5	22,938.7
Fair value
Fair value of financial assets and liabilities
Loans receivable	1,045.0	835.1
Mortgages payable	42.2	80.0
Notes and bonds payable	$ 21,902.2	$ 21,593.5

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No definition available.

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- Definition

Fair value portion of contractual obligation to pay money on demand or on fixed or determinable dates.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2E
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2E

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
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-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

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- Definition

Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-10

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- Definition

Fair value portion of notes payable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-SubTopic 10
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-Publisher FASB
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Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
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-Name Accounting Standards Codification
-Section 50
-Paragraph 2E
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-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2E

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
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-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

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-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
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-Paragraph 1
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

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